From the Guidelines
Normal liver stiffness values in FibroScan typically range from 2 to 7 kilopascals (kPa) for healthy individuals without liver disease. FibroScan, also known as transient elastography, measures liver stiffness as an indicator of fibrosis or scarring. According to the most recent and highest quality study 1, values between 7-10 kPa suggest mild to moderate fibrosis, while readings between 10-14 kPa indicate advanced fibrosis. Values above 14 kPa are generally consistent with cirrhosis.
The study 1 recommends using a simplified rounded value of 8.0 kPa as the low cutoff to exclude clinically significant fibrosis and 12.0 kPa as the upper cutoff, indicating that clinically significant fibrosis is likely. These thresholds may vary slightly depending on the underlying liver condition, with different cutoffs sometimes used for viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease.
It's essential to note that FibroScan results should always be interpreted in the context of other clinical findings, laboratory tests, and the patient's medical history. Factors such as recent food intake, inflammation, cholestasis, and congestive heart failure can artificially elevate readings, potentially leading to overestimation of fibrosis. For accurate assessment, patients should fast for at least 3 hours before the examination, as meal ingestion increases liver stiffness values irrespective of the method used for its measurement 1.
In addition, the European Association for the Study of the Liver (EASL) clinical practice guidelines on non-invasive tests for evaluation of liver disease severity and prognosis - 2021 update 1 support the use of liver stiffness measurement (LSM) by transient elastography (TE) to rule-out and diagnose advanced fibrosis and cirrhosis, with cut-offs of <8-10 kPa to rule-out and >12-15 kPa to rule-in. However, the most recent and highest quality study 1 provides more specific and simplified cutoffs, which should be prioritized in clinical practice.
Key points to consider when interpreting FibroScan results include:
- Normal values: 2-7 kPa
- Mild to moderate fibrosis: 7-10 kPa
- Advanced fibrosis: 10-14 kPa
- Cirrhosis: >14 kPa
- Low cutoff to exclude clinically significant fibrosis: 8.0 kPa
- Upper cutoff indicating clinically significant fibrosis: 12.0 kPa
- Factors that can artificially elevate readings: recent food intake, inflammation, cholestasis, and congestive heart failure
- Requirement for accurate assessment: patients should fast for at least 3 hours before the examination.
From the Research
Normal Liver Stiffness Values
- The normal liver stiffness values in FibroScan (Fibrosis Scan) are considered to be below 6 kPa, as stated in the study 2.
- Another study 3 found that the mean value of liver stiffness in patients with no fibrosis (F0) was around 5.8 kPa.
- A study on non-alcoholic fatty liver disease (NAFLD) patients found that liver stiffness measurements (LSM) below 6.1 kPa were associated with no fibrosis or mild fibrosis (F0-F1) 4.
- It is essential to note that liver stiffness values can be influenced by various factors, including hepatic inflammation, as reported in the study 5, which found that liver inflammation activity can affect the diagnostic accuracy of FibroScan.
Liver Stiffness Cut-off Values
- The cut-off values for liver stiffness measurements (LSM) in FibroScan are:
- These cut-off values may vary depending on the population being studied and the presence of confounding factors, such as liver inflammation.
Factors Affecting Liver Stiffness Measurements
- Liver stiffness measurements can be affected by various factors, including:
- Hepatic inflammation, as reported in the study 5
- Steatosis (measured by controlled attenuation parameter [CAP]) 6
- Weight loss and physical activity, as reported in the study 6
- Venous pressure (e.g., during liver congestion) 2
- Hepatic infiltration with tumor cells, mast cells (mastocytosis), inflammatory cells (all forms of hepatitis), or amyloidosis 2